error: incompatible types: unexpected return value : Java 8 [duplicate]

Question

I have written a simple method which returns the boolean value.

private boolean isActionAvailable(Collection<StudentConfiguration> studentConfigs){
       if(studentConfigs != null)
        {
            studentConfigs.forEach(studentConfig -> {
                if(studentConfig.action() == null || !studentConfig.action().equals(Action.DELETE)) {
                    return true;
                }
            });
        }
        return false;
    }

The method is throwing the following exception .

error: incompatible types: unexpected return value
            studentConfigs.forEach(studentConfig -> 

What's the problem with my code?

Answer 1

The lambda expression passed to forEach shouldn't have a return value.

It looks like you want to return true if any of the elements of the input Collection satisfies a condition:

private boolean isActionAvailable(Collection<StudentConfiguration> studentConfigs){
    if(studentConfigs != null) {
        if (studentConfigs.stream().anyMatch(sc -> sc.action() == null || !sc.action().equals(Action.DELETE))) {
            return true;
        }
    }
    return false;
}

As Holger suggested, this can be reduced to a single statement:

return studentConfigs != null && studentConfigs.stream().anyMatch(sc -> sc.action() == null || !sc.action().equals(Action.DELETE));

or

return studentConfigs != null ? studentConfigs.stream().anyMatch(sc -> sc.action() == null || !sc.action().equals(Action.DELETE)) : false;